• 한국환경보건학회지
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• 제33권4호
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• pp.317-324
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• 2007

The sewage treatment sludge disposal has become a serious environmental problem because of restricted direct land-filling and oceandumping in spite of their large amounts discharged. So the recycling of sewage treatment sludge is very useful alternative for waste management. Here, we studied the feasibility of zeolite synthesis in open system from the sewage treatment sludge incinerator fly ash by means of hydrothermal synthesis. We considered the concentration of NaOH, reaction time, reaction temperature and reaction step as synthesis variables. The phase of zeolite products was identified by X-ray diffractometer(XRD) and ammonium ion exchange test was performed for the raw fly ash and two zeolite products(Z-3 and Z-5). In leaching test of the raw fly ash, hazard metal is detected very low level compared with regulatory leaching test standard. But in total recoverable test, the total contents of the fly ash were very high in terms of the standard for waste-derived fertilizer. Through hydrothermal reaction, small amount of zeolite P was synthesied in 1 N of NaOH solution and relatively large amount of hydroxysodalite was synthesied in 3 N and 5 N of NaOH solution with similar peak intensity. Addition of an aging step in the synthesis didn't increase the amount of zeolite phase. Maximum $NE_4^+-N$ exchange capacity is 1.49 mg $NH_4^+-N/g$ in Z-3 and 1.38 mg $NH_4^+-N/g$ in Z-5. Most of the ammonium ion is exchanged in 30 minutes and disorption did not occur until 5 hours.

• 한국지반공학회논문집
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• 제34권12호
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• pp.43-58
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• 2018

본 연구에서는 매입말뚝 주면부의 하중전이 거동을 확인하기 위하여 14본의 강관매입말뚝에 대한 정재하시험을 수행하였다. 정재하시험을 통하여 하중-침하 곡선 및 축하중 분포를 계측하였으며, 그 결과 말뚝-지반 사이에서 발생되는 주면마찰력을 정량화 하였다. 이를 토대로 강관매입말뚝의 일반적인 하중전이곡선 형태를 도출하였다. 본 연구 결과, 말뚝의 주면하중전이 거동은 연성과 취성파괴 두 가지 형태로 나타났다. 그 결과, 강관매입말뚝의 t-z 곡선을 쌍곡선(일수현상이 없는 경우)과 톱니 형태(일수현상이 있는 경우 또는 표준관입저항치, $N{\geq}50$인 풍화암 이상)로 각각 제안하였다. 그때의 최대주면마찰력은 쌍곡선의 경우 지반의 N치 또는 암반의 일축압축강도, 톱니 형태의 경우 주입된 시멘트풀에 의해 형성된 쏘일-시멘트층의 일축압축강도의 영향을 받는 것으로 나타났다.

• 한국간호교육학회지
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• 제5권2호
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• pp.300-314
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• 1999

This study is an attempt to evaluate the effect of the medication and symptoms self-care education on the psychiatric patients' quality of life. This exploratory study was designed to a quasi-experiment of pretest-postest with a non equivalent control group. Subjects of 40 patients who were discharged from a mental hospital in Pusan were selected to be experiment and control group, with each group consisting of 20. The research period was from March, 6 to May, 29, 1999 and the pre-post test was given before and after implementing MSSE to the both experiment and control group. The results finding were summarized as follows ; 1. subjects who attended self-care education scored significantly higher than control group in quality of life.(Z=-2.06, P=0.034) 2. Those who were in the experiment group reported more significant higher scores than control group in item of quality of life, living situation(A=-2.62 P=0.012), relations with spouse (Z=-2.31 P=0.038) and children (Z=3.37, P=0.008), fear (Z=-1 95, P=0.049) and anger(Z=-2.07 P=0.041), work functioning (Z=-2.34, P=0.021), environmental adjustment. (Z=-2.05, P=0.039)

• 유통과학연구
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• 제21권7호
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• pp.21-31
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• 2023

Purpose: The purpose of this study is to investigate how to perceive the role of the slow city and provide policy and managerial implications on the necessity of the slow city management and distributional values based on perspectives of millennials and generation Z. This study examined i) how do millennials and generation Z perceive economic, environment, cultural, community, and quality of life factors on attitude toward the slow city? ii) how does attitude affect overall satisfaction and intention to recommend the slow city to other cities' residents? iii) how do millennials perspectives on proposed factors differ from generation Z? Research design, data and methodology: This study conducted an online survey and applied t-test, factor, ANOVA, and regression analysis. Results: This study found that effects of economic and quality of life factors on attitude toward the slow city showed significance in cases of millennials and generation Z, while effects of environment factor on overall attitude showed significance in the case of generation Z. Conclusions: Governments should foster how millennials and generation Z understand the meanings of the slow city to form a better attitude in a society and put efforts to build a better image and management of the slow city.

• Journal of Electrical Engineering and Technology
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• 제11권6호
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• pp.1769-1776
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• 2016

For on-line partial discharge (PD) monitoring of rotating machines, a novel sensor is proposed, which can be installed on the power lead inside the terminal box of the machine. The sensor has been designed to have high capacitance, and minimal reflection of measured pulses. As a sensitivity of the sensor, transfer impedance $Z_t$ has been measured and compared to conventional coupler-type sensors. A simple method is presented for measuring $Z_t$ of coupler sensors, using a vector network analyzer and a practical lead-cable of rotating machine. Through this method, it became possible to measure the $Z_t$ of coupler sensors including the installation environment of them. The $Z_t$ of the proposed sensor is higher than that of same sized other conventional couplers at frequencies between 30 and 92 MHz. Another sensitivity test has been performed using a PD calibrator as a test pulse source. The proposed sensor has higher measured peak voltage than the conventional coupler type sensors when the same charges were input.

• 정보관리학회지
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• 제17권1호
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• pp.129-148
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• 2000

최근 구축된 한글 실험문헌 집단을 대상으로 2-포아송 모형의 Z값의 주제어 식별력을 측정하였으며, 역문헌빈도와 2 포아송 모형간의 상관관계를 분석하였다. 이를 위해 Z와 수정 $\beta$값 및 IDF와 수정 TF.IDF 가중치를 하위 실험집단별로 각기 산출, 비교하였다. 실험 결과 Z값의 주제어 선정능력은 3개의 하위 실험집단 가운데 과학기술분야에서만 확인되었다. 2-포아송 모형의 Z값과 역문헌빈도 가중치간의 상관관계 분석에서는 전문(full text)인 여성학분야 실험집단에 비해 초록 및 신문기사와 같이 단문(short text)으로 구성된 과학기술분야 및 일반사회 분야 실험집단에서 상관관계가 더 크게 나타 났다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2005년도 춘계학술대회 논문집
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• pp.468-472
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• 2005

In this paper, the static and dynamic stiffness of the air bearing stage for micro-micro machine tool are examined experimentally. For stiffness and precision concerns, air bearing stages are adapted for 3-axis micro-milling machine which is size of $200x200\;mm^2$. The air bearings in the stage are preloaded by permanent magnets to achieve desired bearing clearance and stiffness for vertical direction. As the stiffness of the air bearing is primary interests, static stiffness test were performed on XY stage in Z direction and Z column in Y direction. Dynamic test were performed on XY stage and Z column, respectively. Both static and dynamic tests were performed in different air pressure conditions. The vertical stiffness of XY stage is about 9 N/ pm where Y stiffness of Z column is much smaller as $1\;N/{\mu}m$ because of the large moment generated by Y force on the column.

• 한국산학기술학회논문지
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• 제22권2호
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• pp.632-637
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• 2021

현재 미래의 건설 산업 기술을 발전시키고자 최근 미래 산업으로 각광받고있는 3D 프린팅을 이용한 콘크리트의 시공기술을 활용하여 구조물을 건설하는 연구가 국내외 건설업계 및 학계에서 활발히 진행되고 있다. 하지만 현재 개발되고 있는 3D 프린팅 기술은 적합한 시공기술, 콘크리트 재료 자체의 물성이 사용기준에 미치지 못하고 실제 현장에서 적용하기가 어려운 상황이다. 또한 시공된 구조물에 대한 내구성 관리 및 유지관리를 위한 연구가 필요한 실정이다. 본 연구에서는 Material extrusion 방식으로 출력한 3D 프린팅 콘크리트를 각각의 적층 방향 X, Y, Z축으로 나누어 측정한 압축강도와 휨강도를 기존의 몰드에 제작한 시험체와 비교 분석하였다. Test direction II Z축의 시험체의 압축강도가 나머지 Test direction I, III Y축, X축의 시험체에 비하여 8~10%의 높은 강도를 발현하였고 몰드 제작 시험체와 비교하였을 경우 4%가량 낮은 강도를 발현하였다. 휨강도 측정결과 재령 28일 기준으로 Test direction II Z축 방향의 시험체의 휨강도가 Test direction I, III Y축, X축의 시험체에 비하여 5~7%의 높은 강도를 발현하였고 몰드 제작 시험체와 비교하였을 경우 2%가량 낮은 강도를 나타내었다.

• 한국콘텐츠학회논문지
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• 제17권3호
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• pp.633-642
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• 2017

본 연구는 교류분석 프로그램이 육군 부적응 병사들의 개인역량과 의사소통 능력에 미치는 효과를 파악하기 위한 실험연구로 단일군 전 후 설계이다. 연구대상자는 G시에 소재한 ${\bigcirc}{\bigcirc}$부대 ${\bigcirc}{\bigcirc}$캠프에 참가하고 있는 군 복무부적응 병사 8명이었고, 자료수집기간은 2015년 10월 15일에서 10월 21일까지였다. 교류분석 프로그램은 1주일에 2회, 1회당 240분(2회기)으로 2주 동안 총 8회기로 진행하였으며, 자료 수집은 실험군에게 사전-사후 자기기입식 설문방법으로 진행하였다. 자료 분석방법은 Wilcoxon의 부호순위 검정을 이용하였고, 연구결과에서 실험군은 사전에 비해 사후에 개인역량(Z=-2.366, P=.018). 개인역량의 하위요인 중 자기효능감(Z=-2.047, P=.041), 긍정성(Z=-2.058, P=.040)이 유의하게 증가하였다. 개인역량 하위요인 중 대인관계(Z=-1.179, P=.238), 군 입대 동기의 자발성(Z=-1.518, P=.129)과 의사소통 능력은 평균점수가 높아지긴 하였으나 통계적으로 유의한 차이는 없었다(Z=-1.524, P=.128). 결론적으로 본 연구에서 사용된 교류분석 집단상담이 개인역량, 자기효능감, 긍정성을 향상시켜 군 적응을 돕는데 효과적임을 시사한다.

• Archives of Pharmacal Research
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• 제26권1호
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• pp.34-39
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• 2003

The traditional Asian medicinal herb, roots of Astragalus (A.) membranaceus (Leguminosae), is used for many purposes, some of which are purported to stimulate the release of growth hormone in vivo. Extracts of A. membranaceus were tested to determine whether they stimulate the release of growth hormone in rat pituitary cell culture. A. membranaceus was extracted sequentially with 80% ethanol (fraction A), n-hexane (fraction B); the test compound from the herbal extraction was isolated using silica gel column chromatography and was identified with spectral data. Test compound was also extracted by traditional boiling water methods. Induction of growth hormone in pituitary cell culture was conducted with isolated compounds and extracted fractions of A. Radix (dried roots of A. membranaceus). The fraction A was not active in the rat pituitary cell culture, but the fraction B derived from the ethanol fraction stimulated the release of growth hormone in culture. Six compounds from fraction B (1-6) were isolated and identified previously. The compounds 1,2-benzendicarboxylic acid diisononylester (1), $\beta$-sitosterol (2), and 3-Ο-$\beta$-D-galactopyranosyl-$\beta$-sitosterol (5) did not induce growth hormone release in the culture. Formononetin (3), 9Z, 12Z-octadecadienoic acid (4), stigmast-4-en-6$\beta$-o1-3-one (6) and 98-E, a mixture of 1'-9, 12-octadecadienoic acid (Z,Z)-2',3'-dihydroxy-propylester (7) and 1'-hexadecanoic acid-2',3'-dihydroxy-propylester (8) stimulated the release of growth hormone in the rat pituitary cell culture significantly compared to the control. In conclusions, four compounds isolated from extracts of A. Radix induced growth hormone release in the rat pituitary cell culture. The 98-E isolate was the most active inducer of growth hormone release.